| 1 | /* |
|---|---|
| 2 | * Copyright (C) 2007-2010 Júlio Vilmar Gesser. |
| 3 | * Copyright (C) 2011, 2013-2020 The JavaParser Team. |
| 4 | * |
| 5 | * This file is part of JavaParser. |
| 6 | * |
| 7 | * JavaParser can be used either under the terms of |
| 8 | * a) the GNU Lesser General Public License as published by |
| 9 | * the Free Software Foundation, either version 3 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * b) the terms of the Apache License |
| 12 | * |
| 13 | * You should have received a copy of both licenses in LICENCE.LGPL and |
| 14 | * LICENCE.APACHE. Please refer to those files for details. |
| 15 | * |
| 16 | * JavaParser is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU Lesser General Public License for more details. |
| 20 | */ |
| 21 | package com.github.javaparser.ast.expr; |
| 22 | |
| 23 | import com.github.javaparser.TokenRange; |
| 24 | import com.github.javaparser.ast.AllFieldsConstructor; |
| 25 | import com.github.javaparser.ast.Generated; |
| 26 | import com.github.javaparser.ast.Node; |
| 27 | import com.github.javaparser.ast.NodeList; |
| 28 | import com.github.javaparser.ast.body.Parameter; |
| 29 | import com.github.javaparser.ast.nodeTypes.NodeWithParameters; |
| 30 | import com.github.javaparser.ast.observer.ObservableProperty; |
| 31 | import com.github.javaparser.ast.stmt.BlockStmt; |
| 32 | import com.github.javaparser.ast.stmt.ExpressionStmt; |
| 33 | import com.github.javaparser.ast.stmt.ReturnStmt; |
| 34 | import com.github.javaparser.ast.stmt.Statement; |
| 35 | import com.github.javaparser.ast.visitor.CloneVisitor; |
| 36 | import com.github.javaparser.ast.visitor.GenericVisitor; |
| 37 | import com.github.javaparser.ast.visitor.VoidVisitor; |
| 38 | import com.github.javaparser.metamodel.DerivedProperty; |
| 39 | import com.github.javaparser.metamodel.JavaParserMetaModel; |
| 40 | import com.github.javaparser.metamodel.LambdaExprMetaModel; |
| 41 | import java.util.Optional; |
| 42 | import java.util.function.Consumer; |
| 43 | import static com.github.javaparser.utils.Utils.assertNotNull; |
| 44 | |
| 45 | /** |
| 46 | * <h1>A lambda expression</h1> |
| 47 | * <h2>Java 1-7</h2> |
| 48 | * Does not exist. |
| 49 | * <h2>Java 8+</h2> |
| 50 | * {@code (a, b) -> a + b} |
| 51 | * <br>{@code a -> ...} |
| 52 | * <br>{@code (Long a) -> { println(a); }} |
| 53 | * <p/>The parameters are on the left side of the ->. |
| 54 | * If a parameter uses type inference (it has no type specified) then its type is set to {@code UnknownType}. |
| 55 | * If they are in ( ), "isEnclosingParameters" is true. |
| 56 | * <br>The body is to the right of the ->. |
| 57 | * The body is either a BlockStmt when it is in { } braces, or an ExpressionStmt when it is not in braces. |
| 58 | * |
| 59 | * @author Raquel Pau |
| 60 | */ |
| 61 | public class LambdaExpr extends Expression implements NodeWithParameters<LambdaExpr> { |
| 62 | |
| 63 | private NodeList<Parameter> parameters; |
| 64 | |
| 65 | private boolean isEnclosingParameters; |
| 66 | |
| 67 | private Statement body; |
| 68 | |
| 69 | public LambdaExpr() { |
| 70 | this(null, new NodeList<>(), new ReturnStmt(), false); |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Creates a single parameter lambda expression. |
| 75 | */ |
| 76 | public LambdaExpr(Parameter parameter, BlockStmt body) { |
| 77 | this(null, new NodeList<>(parameter), body, false); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Creates a zero or multi-parameter lambda expression with its parameters wrapped in ( ). |
| 82 | */ |
| 83 | public LambdaExpr(NodeList<Parameter> parameters, BlockStmt body) { |
| 84 | this(null, parameters, body, true); |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Creates a single parameter lambda expression. |
| 89 | */ |
| 90 | public LambdaExpr(Parameter parameter, Expression body) { |
| 91 | this(null, new NodeList<>(parameter), new ExpressionStmt(body), false); |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Creates a zero or multi-parameter lambda expression with its parameters wrapped in ( ). |
| 96 | */ |
| 97 | public LambdaExpr(NodeList<Parameter> parameters, Expression body) { |
| 98 | this(null, parameters, new ExpressionStmt(body), true); |
| 99 | } |
| 100 | |
| 101 | @AllFieldsConstructor |
| 102 | public LambdaExpr(NodeList<Parameter> parameters, Statement body, boolean isEnclosingParameters) { |
| 103 | this(null, parameters, body, isEnclosingParameters); |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * This constructor is used by the parser and is considered private. |
| 108 | */ |
| 109 | @Generated("com.github.javaparser.generator.core.node.MainConstructorGenerator") |
| 110 | public LambdaExpr(TokenRange tokenRange, NodeList<Parameter> parameters, Statement body, boolean isEnclosingParameters) { |
| 111 | super(tokenRange); |
| 112 | setParameters(parameters); |
| 113 | setBody(body); |
| 114 | setEnclosingParameters(isEnclosingParameters); |
| 115 | customInitialization(); |
| 116 | } |
| 117 | |
| 118 | @Generated("com.github.javaparser.generator.core.node.PropertyGenerator") |
| 119 | public NodeList<Parameter> getParameters() { |
| 120 | return parameters; |
| 121 | } |
| 122 | |
| 123 | @Generated("com.github.javaparser.generator.core.node.PropertyGenerator") |
| 124 | public LambdaExpr setParameters(final NodeList<Parameter> parameters) { |
| 125 | assertNotNull(parameters); |
| 126 | if (parameters == this.parameters) { |
| 127 | return (LambdaExpr) this; |
| 128 | } |
| 129 | notifyPropertyChange(ObservableProperty.PARAMETERS, this.parameters, parameters); |
| 130 | if (this.parameters != null) |
| 131 | this.parameters.setParentNode(null); |
| 132 | this.parameters = parameters; |
| 133 | setAsParentNodeOf(parameters); |
| 134 | return this; |
| 135 | } |
| 136 | |
| 137 | /** |
| 138 | * @return a BlockStatement or an ExpressionStatement. See class Javadoc. |
| 139 | */ |
| 140 | @Generated("com.github.javaparser.generator.core.node.PropertyGenerator") |
| 141 | public Statement getBody() { |
| 142 | return body; |
| 143 | } |
| 144 | |
| 145 | @Generated("com.github.javaparser.generator.core.node.PropertyGenerator") |
| 146 | public LambdaExpr setBody(final Statement body) { |
| 147 | assertNotNull(body); |
| 148 | if (body == this.body) { |
| 149 | return (LambdaExpr) this; |
| 150 | } |
| 151 | notifyPropertyChange(ObservableProperty.BODY, this.body, body); |
| 152 | if (this.body != null) |
| 153 | this.body.setParentNode(null); |
| 154 | this.body = body; |
| 155 | setAsParentNodeOf(body); |
| 156 | return this; |
| 157 | } |
| 158 | |
| 159 | @Override |
| 160 | @Generated("com.github.javaparser.generator.core.node.AcceptGenerator") |
| 161 | public <R, A> R accept(final GenericVisitor<R, A> v, final A arg) { |
| 162 | return v.visit(this, arg); |
| 163 | } |
| 164 | |
| 165 | @Override |
| 166 | @Generated("com.github.javaparser.generator.core.node.AcceptGenerator") |
| 167 | public <A> void accept(final VoidVisitor<A> v, final A arg) { |
| 168 | v.visit(this, arg); |
| 169 | } |
| 170 | |
| 171 | @Generated("com.github.javaparser.generator.core.node.PropertyGenerator") |
| 172 | public boolean isEnclosingParameters() { |
| 173 | return isEnclosingParameters; |
| 174 | } |
| 175 | |
| 176 | @Generated("com.github.javaparser.generator.core.node.PropertyGenerator") |
| 177 | public LambdaExpr setEnclosingParameters(final boolean isEnclosingParameters) { |
| 178 | if (isEnclosingParameters == this.isEnclosingParameters) { |
| 179 | return (LambdaExpr) this; |
| 180 | } |
| 181 | notifyPropertyChange(ObservableProperty.ENCLOSING_PARAMETERS, this.isEnclosingParameters, isEnclosingParameters); |
| 182 | this.isEnclosingParameters = isEnclosingParameters; |
| 183 | return this; |
| 184 | } |
| 185 | |
| 186 | @Override |
| 187 | @Generated("com.github.javaparser.generator.core.node.RemoveMethodGenerator") |
| 188 | public boolean remove(Node node) { |
| 189 | if (node == null) |
| 190 | return false; |
| 191 | for (int i = 0; i < parameters.size(); i++) { |
| 192 | if (parameters.get(i) == node) { |
| 193 | parameters.remove(i); |
| 194 | return true; |
| 195 | } |
| 196 | } |
| 197 | return super.remove(node); |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * @return if the body of this lambda is a simple expression, return that expression. |
| 202 | * Otherwise (when the body is a block) return Optional.empty(). |
| 203 | */ |
| 204 | @DerivedProperty |
| 205 | public Optional<Expression> getExpressionBody() { |
| 206 | if (body.isExpressionStmt()) { |
| 207 | return Optional.of(body.asExpressionStmt().getExpression()); |
| 208 | } else { |
| 209 | return Optional.empty(); |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | @Override |
| 214 | @Generated("com.github.javaparser.generator.core.node.CloneGenerator") |
| 215 | public LambdaExpr clone() { |
| 216 | return (LambdaExpr) accept(new CloneVisitor(), null); |
| 217 | } |
| 218 | |
| 219 | @Override |
| 220 | @Generated("com.github.javaparser.generator.core.node.GetMetaModelGenerator") |
| 221 | public LambdaExprMetaModel getMetaModel() { |
| 222 | return JavaParserMetaModel.lambdaExprMetaModel; |
| 223 | } |
| 224 | |
| 225 | @Override |
| 226 | @Generated("com.github.javaparser.generator.core.node.ReplaceMethodGenerator") |
| 227 | public boolean replace(Node node, Node replacementNode) { |
| 228 | if (node == null) |
| 229 | return false; |
| 230 | if (node == body) { |
| 231 | setBody((Statement) replacementNode); |
| 232 | return true; |
| 233 | } |
| 234 | for (int i = 0; i < parameters.size(); i++) { |
| 235 | if (parameters.get(i) == node) { |
| 236 | parameters.set(i, (Parameter) replacementNode); |
| 237 | return true; |
| 238 | } |
| 239 | } |
| 240 | return super.replace(node, replacementNode); |
| 241 | } |
| 242 | |
| 243 | @Override |
| 244 | @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator") |
| 245 | public boolean isLambdaExpr() { |
| 246 | return true; |
| 247 | } |
| 248 | |
| 249 | @Override |
| 250 | @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator") |
| 251 | public LambdaExpr asLambdaExpr() { |
| 252 | return this; |
| 253 | } |
| 254 | |
| 255 | @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator") |
| 256 | public void ifLambdaExpr(Consumer<LambdaExpr> action) { |
| 257 | action.accept(this); |
| 258 | } |
| 259 | |
| 260 | @Override |
| 261 | @Generated("com.github.javaparser.generator.core.node.TypeCastingGenerator") |
| 262 | public Optional<LambdaExpr> toLambdaExpr() { |
| 263 | return Optional.of(this); |
| 264 | } |
| 265 | } |
| 266 |
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